TREA

Signalling by continuous ac

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  • CPC
  • H04Q5/08
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Parent Industries

HELECTRICITY H04Electric communication H04QSELECTING H04Q5/00Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange

Current Industry

H04Q5/08Signalling by continuous ac
Industries

Patents Grantslast 30 patents

  • Information Patent Grant

    Party intercept in selective multifrequency ringing systems
    • Patent number 4,154,987
    • Issue date May 15, 1979
    • Circom, Inc.
    • Roger L. Rosenberg
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3852537
    • Patent number 3,852,537
    • Issue date Dec 3, 1974
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3778557
    • Patent number 3,778,557
    • Issue date Dec 11, 1973
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3689705
    • Patent number 3,689,705
    • Issue date Sep 5, 1972
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3662116
    • Patent number 3,662,116
    • Issue date May 9, 1972
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3450844
    • Patent number 3,450,844
    • Issue date Jun 17, 1969
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3428750
    • Patent number 3,428,750
    • Issue date Feb 18, 1969
    • G08 - SIGNALLING
  • Information Patent Grant

    3301967
    • Patent number 3,301,967
    • Issue date Jan 31, 1967
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3277242
    • Patent number 3,277,242
    • Issue date Oct 4, 1966
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3156776
    • Patent number 3,156,776
    • Issue date Nov 10, 1964
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3144589
    • Patent number 3,144,589
    • Issue date Aug 11, 1964
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3086171
    • Patent number 3,086,171
    • Issue date Apr 16, 1963
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3077577
    • Patent number 3,077,577
    • Issue date Feb 12, 1963
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3035250
    • Patent number 3,035,250
    • Issue date May 15, 1962
    • G08 - SIGNALLING
  • Information Patent Grant

    3009992
    • Patent number 3,009,992
    • Issue date Nov 21, 1961
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2808463
    • Patent number 2,808,463
    • Issue date Oct 1, 1957
    • G10 - MUSICAL INSTRUMENTS ACOUSTICS
  • Information Patent Grant

    2808464
    • Patent number 2,808,464
    • Issue date Oct 1, 1957
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2672151
    • Patent number 2,672,151
    • Issue date Mar 16, 1954
    • G01 - MEASURING TESTING
  • Information Patent Grant

    2604545
    • Patent number 2,604,545
    • Issue date Jul 22, 1952
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2541668
    • Patent number 2,541,668
    • Issue date Feb 13, 1951
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2532125
    • Patent number 2,532,125
    • Issue date Nov 28, 1950
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2408299
    • Patent number 2,408,299
    • Issue date Sep 24, 1946
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2394145
    • Patent number 2,394,145
    • Issue date Feb 5, 1946
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2346420
    • Patent number 2,346,420
    • Issue date Apr 11, 1944
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2246119
    • Patent number 2,246,119
    • Issue date Jun 17, 1941
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2240339
    • Patent number 2,240,339
    • Issue date Apr 29, 1941
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2228113
    • Patent number 2,228,113
    • Issue date Jan 7, 1941
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2202474
    • Patent number 2,202,474
    • Issue date May 28, 1940
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2201296
    • Patent number 2,201,296
    • Issue date May 21, 1940
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    1860457
    • Patent number 1,860,457
    • Issue date May 31, 1932
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE